Process of extracting metals from beryllium minerals



Patented-Feb. 12, 1935- STA ' rnocEss 70F. EXTRACTING METALS-"FROM BERYLLIUM MINERALSL a This invention relates to the extraction of metals fromoresand particularlyacertain silicate ores like beryl now consideredvery.difiicult-and complex in their treatment; This application is k a 'continuatiomimpart ofmy pending application Serial No.; 557,737"filed August 17, 1931.

The usual method of dealingwlthmany complex and silicate ores" on a commercialscale is g so doing, I find that the roasted or-fusedmaterial to' fuse or roast the ground or pulverized ore with fan excess of'sodiurn and potassium carbonates or either. one. The quantityusedof these materialsis usually from one to six times the weight: of

theore. This procedure. is well known in nietalv lur'gy and is used, and recommended 'for silicates which are. called undecomposable in mineral acids. These include the beryls, feldspars, micas and the artificial materials such as glass, porce-' lain, etc. The effect of fusion'is to increase the proportion of base in the silicate and increase thesolubility sothat the silicate is opened up and 1 is usually'made decomposable by acid. Usually I theexcess of alkali in a'fused silicate canbe parbase metals very economicallyby a minimum use tially dissolved out by 'hotw'ater leaching. This fusion method is us uallyapp-lied to silicate ores carrying values sufficient to Warrant the useof so much alkali and subsequent necessary acid.

In many cases, however, the use of one'to six parts of alkali carbonates, to one partfof the ore, places the operation in such an expensive class that this treatment'cann'ot-be consideredand some other method must be u'sedor the ore, or material, is not commercially treatable at all, due to the excessive costs; These fusions also demand'the subsequent use of a large volume of acid and, consequently; a -'-very'large volume of by-products'must be recovered in order to render them at all econ'omical'and inmost cases the byproduct in large quantities is not marketable due to low value, sales and transportation costs and and heating this liquor, the Be(OH) 2 may be precipitatedas described inchemical books generlack of demand.

In my process I recover substantially all 01' the of reagents'which enables, me to treat materials hitherto commercially non treatable due to their excessive treating costs. Also, the by-products are recovered economically ina much more condensedand marketable form and condition. It

also enables me to produce metals and alloy more economically for the same reason.

I now describe the. treatment of beryllium ore, beryl, as an example:

The first step of my process comprises grinding the ore to a suitable degree of fineness. The beryl, which ordinarily contains 10% to. 13% BeO and 13% to 18% A1203, 69% to 70% S102 and amount of sodium carbonate -(anhydrous)'-"orl' otheralkali or neutral salt such as Nah, NaCl, 5,

02012 or CaBs with the groundbcryl and roast-or fuse the inixed material'sufiiciently to partially open up the silicate in theknown manner. By

is'in a condition to be'readilydecomposed}by a 10 strong mineral. acid under pressure and heat. I use just sufficient acid, as'dernanded by' theory,

usually strong H2SO4 of to 66 Be; to} decom;

pose and render .soluble the bases. jInthe case at beryl which usually carries 10 to 12% B60 and 15% to 18% A1203, I find that lthe "al'hollritkof. alkali carbonate never has to'exceed onehalf part of the. alkali to onepa'rt, byvveight, 'or beryl the strong acid sa H2SO'4',E' n01 o'r Enos, 'thor oughly'mix itw'ith the iusedniat'eriaLwhich may or maynot have been leached with'waterto r'e move some alkali, p1a'ce'",the .mixture'fin aclosed vessel. Heat and'pressure; either internal or external, is 3 applied "until the acid; has thbr 5 oughly decomposed the material and hasturned the Bet.) and Al2Os contents into scli'ible-saltsof the strong acid.- Theminimum is 10 pounds per square inch at 212 but higher pressures and temperatures shorten the treatment. The salts are very soluble inwater aridfthe silicaresidue is notina jelly or se1ni -colloidal condition but is in a fine powder'thatf is easily-removed by filtr'a tion, and finds a ready market. v

' 'I'he filtrate liquorcarfrying the dissolved berylhunt and aluminum salts-and a trace of iron is then treated with an excess of an alkali such as NaOl-I, which precipitates the iron and keeps the beryllium and aluminum in solution. On diluting ally. But by heating the strong solution above atmospheric pressure, a precipitation of dense used and also thoseas lowas 10 pounds per a Q square inch, but prolonged treatment is necessary in this latter case.

The pressure precipitation from the strong cipitating the aluminum with a suitable alkalireagent, say NaOH. Evaporation recoversthe NazSO4 in the usual commercial manner, if H2304 was used in the digestionand precipitation steps. i r I;

I have found that the reduction of my dense beryllium hydroxide to metal maybe carried out" at a much lower temperature and the metal is in shape to be remelted into a very dense,,useful form. Also, the alloys of beryllium and other metals are formed much more readily and of a denserstructure when this dense beryllium hydroxide is, used with the other metallic components of the alloy.

While I have described in these examples the application of the process to beryl ores, these being silicates I do not limit myself, however, to the treatment of silicates for the reason that the, process is very much broader and covers the economical treatment of many complex and hitherto diificultly treatable naturally occurring beryllium combinations. The only requirement is that they be. attackable at high temperatures by alkali metal carbonates. It is believed that all' known natural beryllium combinations may be so fopened' up.

I claim as my invention:

1. The process of precipitating beryllium hydroxide from an alkaline aqueous solution containing beryllium associated with the negative radicals of strong mineral acids which comprises alkalinizing said solution with an alkali-metal hydroxide; heating such solution in a closed space until a minimum pressure of 10 pounds per square inch above atmospheric pressure has been held until a copious precipitate of beryllium hydroxide is produced. r

2. The process of extracting beryllium from beryl which comprises finely grinding the crude beryl, mixing therewith a minimum of one-fifth to a maximum of one-half of the Weight of the mineral in anhydrous sodium carbonate, then fusing until substantial reaction takes place, cooling, digesting the resultant mass with sulfuric acid under at least 10 pounds per square inch of pressure above that of the atmosphere and 212 F. until the beryllium has been substantially converted into a salt of the acid used; then leaching the mass with water, adding NaOH to alkalinity and heating the resultant solution under 10 pounds or greater pressure until beryllium is substantially entirely precipitated as hydroxide.

3. The process of extracting beryllium from metals containing it which comprises grinding the mineral, mixing it with an alkali-earthmetal-containing-neutral-salt, heating the mixture to the reacting point, digesting the resultant mass at least;212 F. with a strong mineral acid under a pressure at least 10 lbs. per square inchgreater than atmospheric, leaching the resultant mass with water, alkalinizing the water extractwith NaOH, removing the iron hydroxide precipitated by the alkalinizing step and then precipitating beryllium hydroxide from the remainder of the extract by heating said extract' under .50 lbs; per square inch pressure under conditions where this pressure is generated by the amount ofheat supplied.

4. The process which comprises fusing a beryllium containing mineral with one-fifth to onehalf parts by weight of an alkali-metal carbonate to one partof the mineral, then adding sufficient concentrated mineral acid to neutralize the residual alkali and to render the metallic bases soluble; heating this mixture at a minimum of 10 lbs. per square inch above atmospheric pressure and 212 F. until the BeO content has'been substantially convertedinto a water soluble salt of theadded acid then leaching out said soluble salt with water, heating the said solution in the presence of an alkali-metal hydroxide in a closed space until a minimum pressure of 10 lbs. per square inch above atmospheric pressure is reached and holding the solution in such state until a precipitate of dense beryllium hydroxide is produced. 1

5. The proces of extracting beryllium from minerals containing it which comprises finely grinding the crude mineral, then mixing it with an alkali-metal carbonate, heating the mixture at least -to the fusion point of the carbonate, digesting the resultant mass with a strong mineral acid under pressure greater than atmospheric, leaching the resultant mass with water alkalin-iz'ing the water extract with NaOI-l, removing the iron hydroxide precipitated by the alkalinizing step and then precipitating the beryllium hydroxide from the remainder of the extract by heating the latter to a pressure of 50 lbs. per square inch for at least 10 minutes.

I HARRY H. ARMSTRONG. 

